


the other('s) reason

by Sin_Cognito



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell, Dadster, Implied/Referenced Domestic Violence, Implied/Referenced Underage Sex, M/M, Underfell Papyrus, Underfell Sans, Underfell W. D. Gaster, W. D. Gaster Being An Asshole, collaring, go away, it's really not a happy fic
Language: English
Status: Completed
Published: 2017-10-23
Updated: 2017-10-23
Packaged: 2019-01-21 21:33:36
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,892
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12466372
Author URL: https://archiveofourown.org/users/Sin_Cognito/pseuds/Sin_Cognito
Summary: Papyrus has a present for Sans.





	the other('s) reason

**Author's Note:**

> Someone wanted to know my headcanon as to why/how Sans got his collar.
> 
> I'm not that happy with the way the fic turned out, I may have been too implicit for people to understand what's going on, so DON'T HESITATE TO ASK ME FOR CLARIFICATION. I mean, really there are a lot of implied feelings and all so, just, ask me if you're unsure... And if really nobody understands anything, I'll rework on it.

_Sans hates experimentation time._

_First, he has to put on a gross and old blouse that smells funny. Daddy says he should get used to the smell and stop complaining. Hearing Sans complain gives him migrains he says. Then he must wash his body in the dirty shower. It’s dirty because no one cleans it up. Sometimes there's warm water so he doesn't always mind. But the tiles under his feet are always cold when he gets out of the tub. Or when he's removed from it. After, daddy rubs a products on Sans' body. He doesn't like to be touched. Daddy's too rough. And the product sticks._

* * *

 

 

 

"SANS ! I'M HOME !"

Papyrus barely had the time to take off his boots that a little and chubby skeleton crushed him in a hug. He felt two arms wrap themselves around his waist. After he placed a little kiss upon the other’s skull, Sans finally lifted his head, showing the toothy smile Papyrus loved so much.

"welcome home Boss !"

It was rare to see Sans get that excited. Usually, the lazy skeleton wouldn’t bulge from the couch when Papyrus came home. Sometimes he wouldn’t even wake up… He must’ve been as impatient for Papyrus to come back as Papyrus himself.

Papyrus had been dismissed earlier by Undyne because of an impending storm. She had said it would be better for him to leave before it reached Snowdin and he was buried in the snow, and never mind training, he could just jog all the way back home to make up for the shortened session. He had to admit she had been right because as soon as he had reached the little town, the fog had thickened and the winds had got stronger.

But now that he was home and in Sans' arms, the weather was but a distant memory.

"How was your day my love ?" The tall skeleton asked.

 

 

 

* * *

_He likes waiting in the experiment room. Papyrus is allowed to come. They talk a lot. About everything. Mostly about Papyrus. And also Papyrus does most of the talking._

_Because Sans feels numb and can't talk properly._

 

_It's always so noisy when the experiment starts. Sometimes daddy's assistants come to watch. "a valuable lesson", "a unique experience". Daddy is happy when they say that. But it's not the words that make him happy. Sans knows because he told daddy "a valuable lesson" and "a unique experience" several times and he didn't smile._

_Daddy is famous so he has lots of assistants._

_The assistants are quiet during the experiment. Daddy concentrates and doesn't speak. The room is noisy. Someone is always screaming. Sans wishes they’d stop screaming. His ears hurt. And his throat is hoarse._

* * *

 

 

 

And with that, Sans’ excited smile vanished, only to be replaced with his trademark fake grin. The little skeleton detached himself from Papyrus, who took the oportunity to take his armor off.

"dogamy and dogaressa walked on me while i was… taking a 2 mins break. they were about to report me to undyne but we got called to retreat because of the storm. i got lucky." Sans said with averted eyes.

"Sans, you know I’ve told you to be careful with you napping on the job. I’m fine with you sleeping when I’m patrolling the path to the Ruins because if something goes wrong I can come to protect you. But you really need to stop falling asleep when I’m not around. You only have 1 HP !" Papyrus knew he didn’t need to remind Sans. It had always been that way. Sans would get in trouble, Papyrus would come help him, someone would get hurt. Always. Lucky for them, it had never been Sans. For now. But who could tell when it was going to be him ? Certainly not Papyrus, who grew more and more worried by the day.

"i know but... i was tired y'know... couldnt sleep last night." Sans admitted.

 

 

 

* * *

_Daddy often tells him to speak right and to stop calling him daddy. But  d o c t o r  G a s t e r  is too long to say. Daddy beats him when he calls him just D._

_So he doesn't call him anymore._

* * *

 

 

 

Papyrus wrapped his arms around Sans' middle lovingly. He cupped the other's skull and turned him to be face to face with him.

"Do not worry Sans, I have something to cheer you up." Papyrus said with a lopsided grin.

Then he placed the most gentle kiss on his lips. He wrapped his arms around Sans and carried him to his bedroom. Despite his gruff look, Sans was quite the lightweight. The little skeleton automatically clung to Papyrus, he was used to being carried this way by the much taller and stronger skeleton. Not outside of their home of course, but in here, he was almost always in Papyrus' arms, or on his lap. Not that Papyrus minded. In fact, it was him who most often took Sans in his arms. He knew he had issues with possessiveness but he didn't care. And Sans didn't seem to mind being treated this way by his lover.

Papyrus opened the door with his foot and placed the little skeleton on the bed before sitting next to him. He bent over and captured Sans' mouth in a deep kiss, letting his hands wander wherever they wanted to go. Sans lay down and tried dragging Papyrus with him but the tall one stopped him by putting a firm hand on his chest.

"Stay here" he commanded.

 

 

 

* * *

_"Stop being lazy."_

* * *

 

 

 

Propping himself on his elbows, Sans watched as Papyrus stood up and went to open a drawer in his desk. The guardsman could feel the gaze of his brother on his back, probably wondering what new toy he would bring into their play. But today would be different. Papyrus had waited long enough to give this to Sans.

He turned with two packages in his hands. They were both flat but one was bigger and floppier than the other, which looked more like a box. He went back to the bed and Sans scooted back so that Papyrus could sit down. He then placed the box between them and gave the other package to Sans.

"I got this for you."

"Boss you didnt have to..." Sans said, but Papyrus knew his brother by heart and could see the glint of gratitude in Sans' red eyelights.

 

 

 

* * *

_Sans is not stupid. He has noticed the new and smaller blouse. He knows that sometimes the doctor comes to their room when they're asleep and picks up Papyrus. He doesn't know where the doctor brings his little brother to._

_When he comes back, Papyrus' body is sticky and his voice is hoarse._

 

_Sans asks for more experiments. He doesn't hear the doctor come to their room when they're asleep anymore._

* * *

 

 

 

Sans opened the package and removed a dark gray wool clothing item from its delicate wrapping. Unfolding the fabric, a beautiful yet simple sweater appeared in front of him. There was an intricate pattern on the front and a nice round neck. Sans said nothing and just played with the hems for a while.

"its beautiful Papyrus. thank you."

"Will you wear it to work tomorrow ?" Papyrus asked. He could feel Sans tense.

 

 

 

* * *

_One day, the doctor connects Sans' SOUL with a wire to a machine. It goes bleep bleep. The doctor speaks more than usual. He says difficult words : "artificially bypass the SOUL's input to the autonomic nervous system via regulated CORE machinery."_

_Sans wants to look them up in his dictionnary. But he doesn't know how to spell the words._

 

_Sans doesn't feel his body. It's like it's disconnected from his head. The doctor puts his hand on Sans' neck. Sans feels the sharpness of a knife. The screaming is back. But it stops and Sans can't hear or see anything._

_He doesn't feel his body. It's disconnected from his head._

 

_The doctor smiles and says "I did it ! I did it !"_

* * *

 

 

 

"y-yeah... i, hum, i like it Boss but maybe... its too thick to wear under my red sweater dontcha think ? i can always wear it in the house ! its warmer in here." Sans' gaze was lowered.

"Sans, strip for me."

"WOAH Boss ! isnt it a bit anticlimatic to ask like that ? if you wanted a show you shouldve said so !" Sans was visibly very confused. Papyrus lifted the second present and opened the box himself. Inside was a red leather collar. It was new and in perfect condition. The insides were lined with dark fur. There was a silver buckle on the front and silver spikes all around it.

"is that a... collar ?" Sans asked.

"I want you to put it on."

"you sure spoil me today boss" the little skeleton said with a puzzled look.

"Put it on."

Sans took the collar and was about to put it on but stopped when he realised he couldn't clasp it around his neck with his fluffy turtleneck. He lifted his head up and stared at Papyrus for the longest time. His lips trembled a bit and then he set the collar down in silence. He stripped from his leather jacket and took off his red sweater and white shirt.

There he was, bare chest in front of Papyrus, unable to move. The tall skeleton took the red collar and slided it around the other's neck. He mused the color of the collar was the exact same red as Sans' scar.

 

 

 

* * *

_Sans looks at his neck in the mirror above the sink. He has a red scar there now. The doctor told him not to touch it after he removed the bandage. But the scar is itchy. If he scratches enough, maybe his neck will turn back white._

* * *

 

 

 

"Sans I know you always wear turtlenecks to hide your scar but I don't want you to feel ashamed because of it anymore. You're perfect as you are. Think of this collar around your neck, hiding your scar, as me protecting you. You've fought so bravely, you deserve a rest. What father did to us was wrong. It's not your fault."

A red teardrop fell on Papyrus' hands that were still on Sans' neck.

"It's not your fault" he whispered one last time.

Sans slowly bent over, rested his head against Papyrus' chest and cried. Just cried.

 

 

 

* * *

_Everyday Sans checks Papyrus' neck. He doesn't want his little brother to have a red scar on his neck._

_So he endures it all._

 

_Because there's nothing more important to Sans than Papyrus' safety._

* * *

 

 

 

After what seemed like hours, Sans stopped crying and just sniffed noisily. He sat up straight and brushed the collar with a hand. Then he looked at Papyrus and said : "how do i look ?"

Papyrus smiled. Sans was half naked, the collar was badly adjusted and he could still see the scar underneath. He had dark red rings under his puffy eyes. Snot still dripped from his nasal aperture, dirtying the mattress under him. So he answered with all the honesty he could muster.

"You're the most beautiful monster in the whole world."

As true as Sans had always been there to protect his little brother, Papyrus would always be there to state the obvious to his big brother.

 

Because there was nothing more important to Papyrus than Sans' happiness.

 

**Author's Note:**

> Now, remember the way Papyrus is killed by the human.
> 
>  
> 
> The title is a reference to me not wanting to write yet another Papyrus-gives-Sans-a-collar-to-protect-him-from-dangerous-monsters-by-showing-who-he-belongs-to fic. There are thousands of incredibly well written fics about that already. So it's the other reason I could think of as to why Sans would have a collar. But it's also a reference to Sans and Papyrus' reasons for their actions : to Sans, Papyrus' safety is more important than his happiness, but for Papyrus, it's the opposite.  
> I also want to point out that the present being written in past tense and the past being written in present tense is totally on purpose.


End file.
